Currently, in the industry, a research direction for indoor navigation generally includes an Assisted Global Positioning System (A-GPS) based on a mobile network, a pseudo-satellite (pseudolite), a wireless local area network (WLAN), radio frequency identification (RFID), ZIGBEE, BLUETOOTH (BT), ULTRA-WIDEBAND (UWB) radio, another geomagnetic satellite or terrestrial digital communications, a broadcast signal, infrared positioning, optical tracking positioning, computer vision positioning, ultrasonic positioning, and the like. For the foregoing technologies, a part is mainly used for navigation positioning, and a part is mainly used for communications and can provide a positioning service, for example, the WLAN.
Currently, for indoor positioning for a medium or large-sized building, a distributed antenna system (DAS) is mainly used. The DAS includes a base station, a coupler, a power splitter, and an antenna. Channel information of a terminal device is received using each antenna, and the channel information is returned to a base station device using a feeder when the terminal device sends or receives a signal. The base station compares the obtained channel information of the terminal device with pre-stored channel information of each indoor place, and uses a location closest to the channel information of the terminal device as a location of the terminal device, to implement terminal device positioning.
However, in an actual operation process, channel information of each location pre-stored in a base station is relatively fixed. Due to a change of a surrounding environment (For example, there is another interference signal), channel information constantly changes when a terminal device receives or sends a signal. Consequently, accuracy of terminal device positioning is relatively low.